1. Field of Invention
The present invention relates to a micro-electro-mechanical system (MEMS) sensor, in particular to a MEMS pressure sensor; the present invention also relates to a method for making such MEMS sensor, which is compatible to standard CMOS process.
2. Description of Related Art
MEMS devices are used in a wide variety of products; examples of such applications are absolute and relative sensors such as blood pressure sensor and micro-acoustical microphone. U.S. Pat. No. 6,012,336; U.S. Pat. No. 6,536,281; U.S. Pat. No. 6,928,879; U.S. Pat. No. 7,121,146; U.S. Pat. No. 6,743,654; and U.S. Pat. No. 7,135,149 are relevant art, but the processes employed in these prior art either are too complicated or require equipment or materials which are not compatible to or not standard in CMOS process. A MEMS sensor having a structure which can be manufactured by a standard CMOS process is desired in this industry.